Carbureter.



PATENTED AUG. 18, 1908.

K. G. JOHNSTON. CARBURBI'ER.

ArPLIoATIoN FILED AUG. 12, 1907.

KIRK G. JOHNSTON, OF NEW YORK, N. Y.

CARBURETER.

Specication of Letters Patent.

Patented Aug. 18, 1908.

Application led August 12, 1907. Serial No. 388,151.

To all 'whom it may concern:

Be it known that I, KIRK G. JOHNSTON, a citizen of the United States,residing at No. 61 East Twenty-fifth street, in the city of New York,county of New York, and State of New York, have invented a new anduseful Carbureter, of which the following is a specification.

This invention relates to im rovements in devices for the vcarbuiizationof iquid fuels for y the use of internal combustion engines and theobjects of this invention are, first, to provide a proper mixture offuel and air under all speed and lead conditions of the engine, second,to provide such mixture positively at all times by positive mechanicalaction without dependence on the tension'of springs or other automaticdevices, third, to provide such mixture to the engine as freely aspossible to the end that only slight vacuum tendency is created, fourth,to provide a thoroughlyr reliable carburetor that may be quickly andintelligently adjusted to all requirenients of said internal combustionengines. These objects are attained by the mechanism illustrated in theaccompanying drawing which is iliade part of this specification and inwhich- Figure 1 is a sectional view of the carburetor substantially onthe line A-A of Fig. 3; Fig. 2 is a bottom view of the carbureter(reduced); Fig. 3 isa to view of the carburetor alid Fig. 4 a view o theconnection of the ull rods for thecontrol of the earbureter. he arrowsshow the direction of the flow of air through the carbureter.

Similar numerals refer to similar arts throughout the several figures ofthe t rawn the drawing 15 is the main casting of the earbureter, 16being afuel stand pipe, 17 the connection for the fuel conductor and 19the supporting bar for the fuel stand pipe u these parts are cast inoneieee.

7 is the ca portion of t e carburetor, 7 being the ar or portion throu hwhich is threadedthe guide 2 for the neer le stem 8 as shown at thepoint marked 2^. Threaded into the head 2B of the guide 2 and locked bymeansof the lock nut4is the adjustable stop 3 for the needle stem 8. Adisk 9 is rigidly attached to the stein 8 of the needle 10, its purposebeing to lift the needle 10 du the inrush of air attendin the suctionstrorke of the e ine. The needle stem 8 is squared at its en tofacilitate, b means of a key, the grinding-in of the nee le 10.

Around the fuel stand pipe 16 is an adjustable air pipe 12 having in itslower shell a number of elongated apertures 12B for ythe admission ofair and rovided at its base with an internal thread s iown at 16^ andthumb holds 12^ for its adjustment on the base of the fuel stand pipe16.

Guided on the air pipe 12 is a footl valve 20 which is held in position,but in no case adjusted, by a light tension spring 13 and is stop ed inits rise, when in a position shown by t ie dotted lines at 20B, by thestops 11 which also serve to secure the upper part of the spring 13. Thecylindrical stem portion of this foot valve 20 partly closes theaperture 12u in the air ipe 12, thusermtting the adjustment of t iequantity ofJ air entering said air pipe l2 through the apertures 12E andpermitting full and excessive flow of air ito lthe air pipe 12 when thefoot valve 20 is 1 tei F irnily attached to the head kof the threadedguide 2B is a lever 5 adapted to turn said guide on its thread andthereby raise the said guide 2 and the needlestop 3*; this lever 5conforms in shape to an arc of a circle, of which the length of the ullrod 25^ is the radius, and is of such lengt as to pro- `vide for theshifting of said pull rod 25A a sufficient distance to cause appreciablevariation in the rise of the threaded guide 2.

In the drawing the arc-shaped lever 5 is provided with circular openingsdrilled alon its length into which thebent end of the pu rod 25A may beplaced; it is obvious, how-i ever, that other means of holding said pullrod in proper position on the said arc-shaped lever 5 may be employedwithout departing from the s irit of this invention.

A throttlb 14 operated by a lever 29 and a pull rod '28 is provided, butin case the en gines have other means of being throttled, isunnecessary.`

Fig. 4 shows a simple way of connecting the ull rods of the throttle andcarburetornee le so that they will work in unison: these connectionsmay, however, be made in y a variety of ways in accordance with thecondltlons 1n each case.

While the essential and characteristic features and the referredembodiment of the invention are i lustrated inthe accompanying drawing,it is obvious that the parts are susceptible of modification withoutdeparting from the spirit and intention of this 1nvention, andparticularly, that for heavjT dutv a carbureter embodying this inventioncould be 'constructed havin a plurality of stand pipes with the movab eguides geared to move in unison.

In o eration a fuel tank somewhat higher than t e'carbureter or havingthe fuel under slight air pressure is connected to the carbureter at 17and a connection made to the engine from the opening 6. For the firstadjustment the throttle is nearly closed, with the pull rod 25IL in acom aratively central osition on the arc-shape lever 5; the adjustmentof the carbureter for lowest speed and light load is then made by themanipulation of the air pi e 12 up or down on the fuel stand pipe 16 yturnin on the thumb holds 12^ (see Fig. 2) to reguIate the amount ofairpermitted to enter through the apertures 12 and the manipulation ofthe needle-stem stop Bregulatin the lift permitted to the needle 10 andthe v0W of fuel through the stand pipe 16. This adjustment for low speedand light load being made the throttle is fully o ened, the s ark.advanced and other con itions for hig speed and full load complied with.Opening the throttle has also lifted the threaded guide 2 and the stop 3of the needle 1() thus permitting .the iiow of more fuel into thecarbureter but the resulting mixture of more air and more fuel is notnecessarily the best for complete combustion, therefore a furtheradjustment for high speed and full load is required. Said furtheradjustment is made by shifting the pull rod 25^ along the lever 5 andthus regulating the flow of fuel past the needle v10. On account of thecurvature of the lever 5 the shifting of the pull rod 25A along itslength may be vdone Without disturbing the original adjustment of thecarbureter for low speed and light load. When both adjustments have beenmade according to these directions the throttle may be openedl andclosed to any extent with the assurance that a ro er mixture of fuel andair is always aval ab e.

In further explanation-in a carbureter of the dimensions shown, with thepull rod 25^ in the lever o ening 25 as shown, and with a pull ofthreeourths of one inch for said ull rod, the movement of the lever 5woul be throu h an are of 25 degrees of a circle and the liIt of.theneedle stop would be about .009 of an inch with the same conditionsand the pull rod in the lever opening 27 the lever moved through an areof 18 degrees only and the lift of the sto would be only about .003 ofan inch. In a l cases upon returning the throttle and the lever 5to theposition for low s eed and vlight load', the adjustment woul be exactlythe same as originally made. j

Although the figures given in the explanation would be excellentpractice it does not follow that they are necessary to this invention,but are used to show the variations of adjustment. v

Being aware that carbureters are now in use that employ foot valves,with spring adjustments and air lifted needles with spring stops, I donot claim those features broadly but do claim as new, novel and usefuland'desire to secure by Letters Patent- 1. In a vcarbureter,--an airlifted needle valve, a longitudinally movable guide for saidneedle-valve stem, an adjustable stop for said needle-valve stem in thesaidguide, and a lever attached to said movable guide and adapted tomove same longitudinally varying amounts as and for the purpose setlforth.

2. In a carbureter, the combination of an .raising said guide and stopvertically, as and for the purpose set forth.l

3. In a carbureter; the combination of an air lifted needle valve, afuel stand pipe, an

adjustable air pi e with apertures near its i base around said. uelstand ipe, a foot valve guided on said air piieand) partly covering saidapertures, an' a iinstable and movable stop for said needle va the saidstop and adapted to raise same varyin amounts according to the positionof a u l rod which may be shifted along the ength of said lever,substantially as and for the purposes set forth.

4. In a carbureter, the combinationI of an air liftable needle-valve; a.threaded vertically movable guide for the stem of said nee'- dle-valve;an adjustable sto for the stem of said needle-valve, in said t readedguide; a lever, firmly attached to said threaded guide, adapted to raisesame on its thread; a projectio'n or arbor, from the shell of thecarbureter, through which the saidguide is threaded; a fuel stand pipeprojecting from the base of ve and a lever fixed tol the carburetor andforming the female mem- In testimony whereof I have signed my ber ofsaid air liftable needle-valve; an adname to this specication in thepresence of 10 justable air pipe,dwith aertlllresdindits bae the twosubscribing witnesses.

ortion, surroun in an t rea e to t e 5 Ease of 'said uel stnd i e; afoot valve KIRK G' JOHNSTON' guided on said air pipe and t e shellinclosing Witnesses: the said parts as and for the purpose set E. P.McGEEvooK, forth. RUFUs HOWARD.

